Casement windows are windows in which the glazed panels or sashes are attached to the frame by one or more hinges. Usually the window is hinged vertically, such that the hinges are placed along one side of the window. However, the hinges may also be placed along a top edge (awning window) or a bottom edge.
In order to lock or secure the window in an open or closed position, most casement windows are fitted with a stay or fastener which is connected to the window frame and one side of the glazed panel. In these cases, the window is typically opened and closed by unlatching the fastener or stay and pushing the window open to the required position and then securing the window again using the stay.
Some casement windows, especially larger or heavier windows, are fitted with a winder mechanism which is used to open and close the window. As the handle of the winder is turned in a first direction, a crank arm pushes on a part of the window such that it pivots about its hinges and opens. The window may then be closed by turning the winder handle in the opposite direction.
The design of the winder mechanism is typically such that the window will stay in position when the user stops turning the handle due to the gears in the winder mechanism. Generally, therefore, windows operated using a winder do not include any other fitting to lock the window in position. It is, therefore, possible for a child to open the window simply by turning the handle, without having to disengage any locks or unlatch a fastener. This presents a risk that the child may turn the handle such that the window opens to a distance great enough that the child is able to fall out.
It is an aim of the present invention to overcome at least one problem associated with the prior art whether referred to herein or otherwise.